Sheik Mohammed Abdullah, the "Lion of Kashmir" who dominated politics in this strategically sensitive border state for 50 years, was buried today amid a massive outpouring of grief and an atmosphere of uncertainty about the future of the mountainous province he sought to make virtually autonomous.

Hundreds of thousands of mourners, joined by Indian Prime Minister Indira Gandhi, President Zail Singh and key figures from the Cabinet, accompanied the cortege and paid their last respects to the sheik.

The emotional farewell underscored Abdullah's dominance of affairs in Kashmir for half a century and the imprint he made on India's destiny. But it also spotlighted questions about power succession in this state, which has enjoyed an unusual amount of autonomy and which has sparked two wars between India and Pakistan and clouded relations between India and China. Kashmir's future has wide-ranging implications for the Indian union and Indian-Pakistani relations.

One of the last surviving titans of India's independence struggle and a symbol of secularism who stood alongside Mahatma Gandhi, Jawaharlal Nehru and Khan Abdul Ghaffar Khan in their era, Abdullah was buried at the edge of glittering Lake Dal. He died Thursday at the age of 77 after a series of heart attacks.

The five-mile route from Srinagar's polo grounds, where the chief minister of India's only Moslem state had lain in state, to the Hazrat Bal Islamic shrine, where he was buried, was jammed with hundreds of thousands of mourners, many of whom beat their breasts in anguish and piled flowers on the flat trailer that bore his open coffin.

The sheik's oldest son, Farouk, 45, has been sworn in as acting chief minister of Kashmir, but there have been signs that a power struggle could erupt between moderate and confrontationist forces over Kashmir's relations with India.

In an interview in his home last night, Farouk Abdullah vowed to pursue his father's secular, federated but autonomous policies.

"I have never wanted confrontation with the center [government] nor will I pursue it unless pushed to the line of confrontation . . . . It is for them the central government leaders to decide whether they want to test their strength. My strength is with the people here in Kashmir," Abdullah said.

He said he would attempt to cultivate friendship with Gandhi's government, but warned, "I have no intention of giving more to the center than we already have. We are part of a federated structure and an autonomous state, and I will fight to keep it that way."

Much of the uniqueness of Kashmir in the Indian union and the individuality of the character of its people is owed to Farouk Abdullah's father. In a sense, Kashmir is a microcosm showing the centrifugal forces at work among India's 22 states, but at the same time it is a symbol of the all-India phenomenon and secularism in this vast, diverse nation of 700 million people of differing languages and religions.

Kashmiris speak their own language, have their own flag, pledge loyalty to their own constitution and indulge occasionally in rhetoric about secession. However, most Kashmiris are acutely aware of the region's economic shortcomings and know they could not survive without the union.

In an anomaly unmatched elsewhere in the country, an article of the Indian constitution limits parliamentary powers over Kashmir to defense, foreign affairs and communications, while other constitutional subjects can be applied only with state approval. Non-Kashmiris cannot buy land in the state, and a special annex to the constitution gives Kashmir the power to implement resettlement of former residents and to convey Indian citizenship.

In 1931 -- when Kashmiris were serfs in a feudal system run by a Hindi maharajah -- Sheik Abdullah began to protest anti-Moslem discrimination against a Moslem majority.

Following the partition of the subcontinent into Hindu India and Moslem Pakistan in 1947, Kashmir became an independent monarchy pending negotiations for accession. But after the maharajah finally acceded to India the same year and India and Pakistan fought the first of their two wars over Kashmir, Sheik Abdullah became the state's first prime minister.

Accused of being a traitor, the sheik was jailed by the Nehru government in 1953, and for 22 years--until he made a dramatic accord with Indira Gandhi in 1975--he remained in the political wilderness. He spent 14 years in prisons.

In 1977, the sheik and his party, the National Conference, were swept into office, and he immediately began to battle against concessions made by the state government to the central authority during his absence.

His most controversial move was to support a bill permitting the resettlement in Jammu and Kashmir, as Kashmir is known by its full name, of any Kashmiri living in Pakistan or Pakistani-occupied parts of the state who could prove residence of the state before May 14, 1954.

Apart from raising troublesome questions of whether any state can grant Indian citizenship to nationals of another country, the resettlement bill could worsen Indo-Pakistan relations and darken the difficult prospects for a nonaggression pact between the two countries.

Or as one Western diplomat glumly put it, "There can be no Indo-Pakistan agreement until the Kashmir question is settled, and the resettlement bill is not going to do anything toward settling that issue."

Farouk Abdullah said he, too, would press for its implementation.

However, Abdullah pledged that he would not allow the issue to evolve into communal violence.

The unanswered question in Kashmir is whether Indira Gandhi will attempt to seize the opportunity presented by the death of the strong-willed sheik and assert more central authority in Kashmir, or whether she will be wary of the danger such a move would entail from extremist elements in the state who might force the new chief minister into a confrontationist stand.